In fracture treatment, the concept of stability plays a central role. Two main strategies are commonly used: absolute stability (AS) and relative stability (RS), each with its own indications, techniques, and clinical goals.
Absolute stability aims to achieve rigid fixation at the fracture site, eliminating any movement between bone fragments. This approach focuses on precise anatomical reduction, typically achieved through direct visualization and stable fixation. It is particularly suitable for simple metaphyseal fractures (type A), often treated surgically using open reduction and internal fixation (ORIF) or plate osteosynthesis. The benefits include faster radiographic healing and high mechanical stability, as recommended by the AO Foundation. However, it may require more extensive soft tissue dissection and carries a higher risk of non-union in multifragmentary fractures.
Relative stability, on the other hand, allows controlled micromotion at the fracture site, promoting callus formation and preserving the biological environment. It emphasizes functional reduction—maintaining alignment, rotation, and length—without necessarily achieving perfect anatomical reconstruction. This method is preferred for complex, multifragmentary fractures where maintaining blood supply to the fragments is critical. Minimally invasive techniques like MIPO (Minimally Invasive Plate Osteosynthesis) are commonly used. Although healing may take longer, RS offers a biologically friendly approach and can reduce complications when patients are carefully selected.
A retrospective cohort study compared AS and RS in MIPO plating for humeral shaft fractures (AO/OTA types 12A1 and 12A2). The results showed a significantly shorter median time to radiographic union in the AS group (12 weeks) compared to the RS group (18 weeks). Non-union occurred in 7% of RS cases, and some patients experienced radial nerve palsy. The study concluded that simple fractures benefit from AS constructs, while RS techniques are more appropriate for multifragmentary patterns.
The debate between AS and RS remains active. Surgeons must consider multiple factors—including fracture type, patient condition, and desired outcomes—when choosing the most suitable approach. While AS offers faster healing, RS better preserves biological integrity. Ultimately, both stability concepts are essential tools in modern orthopedic practice and should be applied with expertise and clinical judgment.